1. Field of the Invention
This invention relates to a compressor having an improved vane spring mechanism.
2. Description of the Related Art Developments
U.S. Pat. No. 5,472,327 shows a rotary compressor that comprises a housing having an annular cavity, and an orbital ring piston in said cavity. A pair of slots in said housing slidably support two vanes for movement toward or away from the housing central axis, whereby the vanes cooperate with the outer surface of the ring piston to define variable volume compression chambers. A coil spring is arranged in each vane slot for biasing the vane into pressure contact with the ring piston.
The present invention relates to an improved spring mechanism usable in a vane type compressor for biasing a vane to a desired condition in the compression housing. The improved spring mechanism is designed to achieve an increased service life, while having a relatively low manufacturing cost and installation expense. The improved spring mechanism comprises a torsion spring mounted within a cartridge that can be readily installed in a slot cast into the compressor housing.
The use of torsion springs for vane-biasing purposes in a compressor is old in the art. U.S. Pat. No. 4,789,145 shows a torsion spring seated in a compressor vane slot for vane-biasing purposes. U.S. Pat. No. 2,533,252 shows a torsion spring associated with an arcuate vane in a rotary pump.